Process and apparatus for concentrating acids.



H. W. JONES.

PROCESS AND APPARATUS FOR CONCENTRAHNG ACIDS.

APPLlCATiON FILED NOV-6,1915

Patented May 16, 1916.

E. .EL-

PM BM; W

Y UNITED STATES PATH orrio.

HORACE W. JONE S, OF CHICAGO, ILLINOIS. ASSIGNOR, TO ARMOUR FERTILIZER WORKS,

015 UNIONTOCK YARDS, CHICAGO, ILLINOIS, A CORPORATION OF NEW JERSEY.

rnoonss AND APPARATUS ron conennrnarmo ACIDS.

Specification of Letters Patent.

rams-ea May in, 1916.

'1 b all who; it may concern:

. lie it ltuown that 1, Homer: W. JONES, a

citizen of the United States, residing at +923 Lake larkavenue, L hi'cago, county of (.OOli, State of Illinois, have invented certain new and useful Im n-oveinents in Free: esses and Apparatus for Concentrating Acids; and I do hereby declare the following'to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it appertains to i make and use thesame.

a My invention relates to the concentration of acids, such as sulfuric acid, phosphoric acid, etc, and itcomprises botha novel method of evaporation and of concentration, and a novel apparatus tl11 6f()1..

' In the concentration of acids such as sulfuric acid, etc., by boiling, as practised in evaporating pans heated by direct flame fromvbelow, there is danger of overheating ofthe pan itself. as well as of the acid which it contains. The heat is transmitted through the pan.

the panto the acid sothat the hottest part ofthe acid is where it comes in contact with i i As a result of this-intense localized heating there is also danger of destruction of the paus'by the acid as well as by the direct flame. It has also been heretofore proposed to concentrate the acids by forcing aheated gaseous current up through a tower through which the acid is flowing downward; In this procedure, the heated gases are rapidly cooled," because of the large latent heat of evaporation of the-liquid, so

that the acid is subjected to a, high .temperaturc only in the bottom of the tower,

' and evaporation by the cooler gases in the upper port-ion of thejtower 1s correspondingly dismiuishcd. The partial saturation ofthe gases in their upward passage through the tower also exerts a limiting efl'ect upon the evaporation and concentration of the acid in the upper portions of the tower.

' Also, with such -methods of evaporation,

power'is required for forcing the heated gases through the tower and the acid therein, particularly in those towers Where the gases are forced through. a seriesjof liquid seals at different levels. Proposals have also been made heretofore to effect the concentration of the acid'by direct heat from above, a direct flame or current of highly heated gases being brought into immediate contact with the surface of the acid in the evaporating pans.

Such direct heat against a stagnant body of acid, or against a bodyof considerable depth, is apt to cause local overheating at the surface and accompany- .ing loss of acid, because the conduction of heat through a stagnant body of liquid is very slow.

The present invention relates to a novel apparatus and method for concentrating the acid according to which disadvantages such as those above noted are largely overcome or minimized, and according to which, moreover, the concentration is effected in a simple, rapid and continuous manner, Well adapted for the productionfof concentrated acids for industrial purposes.

1 According to the present invention, the acid is caused to flow down over an irregular inclined surface, in the form of alternate pools and'films, in such a manner that the acid is kept continually in motion, and the particles thereof undergoing continual re-arrangement, so that uniformity of temperature and composition is promoted, and

so that fresh films are being continuously flows, and of the current ofhighly heated gases, may also, with advantage, be such that the gases are discharged upwardly against the inclined surface, or against the lower portion thereof, so that they rise up wardly with respect'thereto, whereby a counter-current action is obtained, and the hottcr gases are brought intodirect contact other gases in'any suitable manner. Where with the already partly concentrated acid "nearer the bottom of the inclined surface.

accompanying drawings,

withresulting concentration. I Theapparatus illustrated is desi lt c'nlarly for l a flame is used, it may be producedby the combustion. of gases or of oil or even'of solid fuel. W here the products of-combns tion contain dust'or other solids or impuri- 5'ties, the acid may be contaminated there with, but for some industrial purposes this slight contamination isnot objectiomrble. WVhere waste heat is available in 'the form .'of--products of combustion from v pyrites I 0 burners or from industrial f n-naces, these can be utilized as the heating gases.

I will now proceed to describe my invention more in detail with particular refetcnce to'the embodin ient, thereof illustrated in the in which- 3 Figure 1 shows, in central longitudinal vertical section, an apparatus embodying the invention, and in which the novel process of the invention can be practised; Fig. 2' 1s a front elevation thereof with parts broken away; and Fig. 3 is a plan view.

The apparatus illustrated comprises a tower or furnace 1, ofrefractory or other material adaptedto resist the action of the '25 heated gases and of the vapors from the acid, having therein an. inclinedwall 2 I which maybe supported below by any suitable filling material 3, and which supports the inclined surface 4: over which the acid The tower or furnace is provided with a top arch 5,.and with a baffle arch- 6 arranged topromote the'upward circulation of the highly heated gases incontact with the acid. A suitable inlet 7 is-prov-ided for the 'hot gases, and, where a direct flame is desired,

a gas or oil'or-other suitable burner 8 is.

also provided. From the top of the apparatus the gases, together with the evaporated liquid, escape through the line 9 either to the atmosphere or to acondenser or washing apparatus or other point of further treatment or use i A feed tank v10 is provided for the acid to be concentrated, and from this tank the 1 acid flows through the'feed pipes 11 having suitable regulating valves therein, to the in' clined surface 4; The evaporated'acid from the bottom ofthe inclined surface his caught in the tank 12 andcan'be led to any suitable place of storage or of further. treatment. The acid can of course be returned and again passed through the apparatus for, 3 further concentration. The inclined surface 4 is of an irregular nature, and, in the embodimcnt of the invention illustrated, is.

made up of horizontally corrugated 'or',i n-

' dented metal or other material. The liquidtobdconcentrated .is caused to flow down this;corrugatedsurface and in doing so' forms alternate ,poolsand films -of-l1qu1d from which-evaporation thereof takes place,

Heconcentration 0 sulfuric ned par- I and of phosphoric acid, but it will be understood that it is adapted for the concentration of other liquids of a similar nature, in a similar manner. For the concentration of sulfuric :-.(:l(l, the inclinedsurface may be made of several sheetso'l'i rust iron, suitably joined together, or of other suitable ma?" terial adapted to resist ,the action of the acid. Similarly, for phosphoric acid, the inclined surface may be made of earthenware or brick or otheracid-resistant material.

In the operation of the ap 'niratus and the practising of the novel method ofconcentrating'therein, the hot air, gas, or lhune, is

discharged into the appnratns'at 7 and imp'inges'on the; evaporating surfaces, after which it is discharged, together with the vapors from thencid through the escape- 3 pipe or. flue 9 to the atmosphere or to other points of treatment or use;

. Because of the continuous ire-arrangement of the particles of the acid in its passage down over the inclined surface, in the form 1 of alternate pools and films, uniformity of temperature I and of composition is proinoted, as well as evaporation from'the' fresh films and surfaces of acid which are continually being formed. Local overheating of the acid at its exposed surfaces is thus prevented or'rninimized, because of the constantly changing character of the film and pool surfaces; "Since the phenomenon of.

evaporation is restrictedfto the exterior free surface of the liquid, the continual re arrangement of the liquid and the'form'ation of fresh surfaces causes the evaporation/totake place, in aparticularly advantageous manner.

Owing to the, fact that the inclined sur-' face itself is protected by the acid flowing over it from direct contact with the flame or other heating gas'cs, danger of overheating is prevented or diminished. It will also and passes downtherethrough, by gravity,

be seen'that the acid is fed to the apparatus,

while the highly heated gases enter the ap-I paratus near its lower portion andpass upwardly therethron-gh in contact witlrthe' 'acid and then escape from the top of the. ap-

paratus without meeting with direct resistance. Accord ngly,- no external apphcatlon of power is, necessary other than .that required for supplying the acid to be evaporated, and for supplyingthe heating gases;

'JH flfjmosgdqta tha ho'tgzascs; substzu xtiiflly s escrilmd. zzppzwatusfmy cniuxmtmiing imicis- 1: 5 am. irregnlm indium? surface and arrangedmica-maxim acid down themovcr in tin: form @f alien 110013411111 filmgimmhs for feeding the and fresh fszirfaces ihwebf,mmtim:-

nf the I A glued. surxhrucfze-d and. arranged t9 acid t0 flow 1mm therecwm' the form of aliematxng pwls'smd fiims, means far each mg the acids W has ccmeemmteci t0 said. sun

fave, an Inlet far a curzfenb of higifly heated gns zs through said aiming err chamber uppo- Sim aha lower 119143.051 01%? said. inclined. stir- ?lace f m directing d gases against the acid flowing 0W1 Said 5 fmje, an mafia; finsaid gases; aim filmevz'igmmted liquhi 1mm the top of the musing G1" chmnber, and a baffle znm'z'lgefi within, the casing or chznnber fgn: musing flu: 11-05:; upwardly in 201% mm Wi'fiik the finwing over said inulined suzrfuca; subsmntiazfly as deacribml In tes simony whereof I 2151 my sigmizm'ea I-KQRACE J'UN ES" 

